Watch



UNITED STATES PATENT OFFICE.

A. L. DENNISON, OF W ALTHAM, MASSAGHUSETTS.

WATCH.

Specification of Letters Patent No. 31,009, dated January 1, 1861.

To all whom "it may concern:

Be it known that I, A. L. DENNISON, of Waltham, in the county ofMiddlesex and State of'Massachusetts, have invented certain Improvementsin Vatches, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, makingpart of this specification, in which Figure l, is a plan of the pillarplate with portions of the internal mechanism necessary to illustrate myinvention. Fig. 2, a plan of the bridge plate. Fig. 3 a section upon theline at :0 of Fig. 1. Fig. it, a plan of the stop wheel. Fig. 5, plan ofthe underside of the intermediate wheel I, with the maintaining powerspring. Figs. 6, 7, S and 9 details of the separate parts of which theintermediate wheel I, is composed and which will be referred tohereafter.

It is well known that it is desirable to reduce the size of watches thatare to be carried about the person not only in thickness but also indiameter so far as this may be done without weakening or otherwiseinjuring the works. It is also very desirable that a watch should have alarge barrel giving a large spring space also a large main gear andparticularly that the pinion with which the main gear engages be largeand that it possesses a great number of teeth. All these ends areaccomplished by means of my present invention which consists in placingthe pinion, which engages with the main gear, upon a supplementary arborout of the center of the watch, which arbor carries an intermediatewheel that engages directly with the center wheel.

I am aware that both in clocks and watches intended to run for a numberof days without winding, an intermediate wheel and pinion have beenemployed between the main gear and center wheel, but in such cases theintermediate wheel has engaged with a pinion upon the arbor of thecenter wheel and not with the wheel itself. But such device which wasused only for the purpose of increasing the number of revolutions of thecenter wheel would not answer the end which I have in view, but would onthe con trary defeat it, as the intermediate wheel and center wheel lieone over the other, and consequently increase the thickness of thewatch, whereas by my arrangement the thickness as well as the diameterof the watch is diminished.

In the accompanying drawings A, is the pillar plate B, the stationarybarrel which is secured to the pillar plate by screws a. The cover platefor the barrel is formed by the main gear 0, through the center of whichpasses the winding arbor D.

The main spring E, is connected at its outer end to the stationarybarrel B, and at its inner end to a hub or collar F, secured to thewinding arbor.

The power of the spring is transmitted to the main gear through theratch G and spring a, the ratch being secured to the arbor and thespring to the gear at 2. The winding arbor and ratch are thus allowed toturn in the direction of the arrow 1, in-

dependent of the gear when the watch is wound up, and to communicate therecoil of the spring to the gear in the opposite direction when thewatch is going. The main gear C, engages with a pinion II, upon thearbor of the intermediate gear I, which engages with the center wheel K.It will thus be seen that instead of the pinion which was heretoforeplaced upon the center arbor, and which limited the size that could begiven to the barrel and main gear, there is only the arbor itself of thecenter wheel which being much smaller than the pinion, leaves much morespace for the enlargement of the barrel and gearor if the size of thebarrel and gear remain the same, permits the diameter of the watch to bediminished. It will also be perceived that if the main gear was crowdedby the pinion the latter was equally crowded by the gear andconsequently the size of this pinion was reduced to the minimum but bythe arrangement above described of an intermediate wheel between themain gear and center wheel, and engaging with the latter, I am enabledto enlarge the pinion with which the main gear engages to any desirablediameter and thus to reduce the disparity between it and its drivingwheel to a degree that shall be practically unobjectionable, But as thepinion is enlarged the power of the main gear upon it increases.Consequently I am enabled to employ a much thinner spring than hasheretofore been used which gives me a double advantage. 1st with a thinspring more turns may be given to the barrel and main gear and thus theamount of motion lost by the use of the large pinion may be made up. 2ndthe thin sprlng is far less liable to breakage and may be temperedhigher than one that is thicker.

The retaining power which drives the train while the watch is beingwound up is attached to the intermediate wheel Lwhich is constructed asfollows. The upper plate or body of this wheel (0 Figs. 1 and 3) isattached to the pinion H and arbor, and has a recess or groove (cZ,) forthe accommodation of the maintaining spring a projection (3,) on thewheel engaging with a corresponding notch (4) in the spring. The plate(a) is turned down upon its periphery to a depth equal to the depth ofthe groove (cl) and upon the ledge (50) thus formed, is placed thetoothed ring (g,) having a notch into which enters the hooked end of thespring (f). The under plate (h,) of the wheel is now secured to theplate (0) by screws (2') (Figs. 1 and 3) there being sufhcient spacebetween them to prevent them from binding the ring (6 and allow thelatter to moveindependently of the balance of the wheel. The plate (h,)is also the ratch of the maintaining power and is seen in section inFig. 3, detached in Fig. 7, and dotted in Fig. 2 together with its pawland spring (Z It will be seen on inspection of Fig. 8, that the wheel(I) lies partly within a recess turned in the bridge plate so that theratch. (h) is brought upon a level with its pawl (m,) and spring (Z)which are secured to the under surface of the bridge plate. By thusplacing the retaining power upon the intermediate wheel I am enabled toplace the ratch of the retaining power in the same plane with the ratchof the winding barrel and thus to save the space in the thickness of thewatch heretofore occupied by one of them; were the maintaining powerplaced upon the winding arbor the two ratches would necessarily fall oneabove the other and would occupy a double amount of space.

In Fig. 4:, is seen detached the stop wheels 1 and 2, which are attachedto the top of the bridge plate as seen in Figs. 2 and 3.

)Vhat I claim as my invention and desire to secure by Letters Patentis- 1. The intermediate wheel I in combination with the main gear C, andcentral wheel K, when the intermediate and central wheels are in thesame plane as set forth.

2. Combining the maintaining power with an intermediate wheel betweenthe main gear and the central wheel, whereby the ratch of the windingarbor and the ratch of the maintaining power are placed in the sameplane for the purpose set forth.

A. L. DENNISON. )Vitnesses:

WM. H. KEITH, HENRY MARTYN.

